Sleep deprivation can attenuate light-induced phase shifts of circadian rhythms in hamsters.
To determine whether sleep deprivation (SD) affects the response of circadian rhythms to light, hamsters were forced to walk on a slowly rotating treadmill for 6 or 24 h, ending early in the night, with or without a light pulse during the last 30 min. SD alone did not produce a significant phase shift. Light pulses (300 and 50 lx) alone induced significant delay shifts (55 and 35 min, respectively). Twenty-four hours SD significantly attenuated the delay to brighter light and 6 h SD significantly attenuated the delay to moderate light. Sleep loss or attendant low-intensity continuous activity appear to modulate the response of the hamster circadian system to light.
Mistlberger
R E
RE
Department of Psychology, Simon Fraser University, Burnaby, BC, Canada. mistlber@sfu.ca
Landry
G J
GJ
Marchant
E G
EG
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D006224:Cricetinae / Q000502:physiology*; D008297:Male; D009043:Motor Activity; D017440:Photoperiod; D012892:Sleep Deprivation / Q000502:physiology*